Ionic Strength‐Mediated “DNA Corona Defects” for Efficient Arrangement of Single‐Walled Carbon Nanotubes

Abstract Single‐stranded DNA oligonucleotides wrapping on the surface of single‐walled carbon nanotubes (SWCNTs), described as DNA corona, are often used as a dispersing agent for SWCNTs. The uneven distribution of DNA corona along SWCNTs is related to the photoelectric properties and the surface activity of SWCNTs. An ionic strength‐mediated “DNA corona defects” (DCDs) strategy is proposed to acquire an exposed surface of SWCNTs (accessible surface) as large as possible while maintaining good dispersibility via modulating the conformation of DNA corona. By adjusting the solution ionic strength, the DNA corona phase transitioned from an even‐distributed and loose conformation to a locally compact conformation. The resulting enlarged exposed surface of SWCNTs is called DCDs, which provide active sites for molecular adsorption. This strategy is applied for the arrangement of SWCNTs on DNA origami. SWCNTs with ≈11 nm DCD, providing enough space for the adsorption of “capture ssDNA” (≈7 nm width required for 24‐nt) extended from DNA origami structures are fabricated. The DCD strategy has potential applications in SWCNT‐based optoelectronic devices.


Ionic
Figure S1.Quantifying free ssDNA desorbed from the surface of SWCNTs with NaCl concentration changes.a) Schematic diagram of the process for quantifying free ssDNA desorbed from the surface of SWCNTs.b) The histogram showed that the concentration of free ssDNA at low salt concentration is significantly higher than that at high salt concentration.

Figure S2 .
Figure S2.Normalized fluorescence intensity of ssDNA-SWCNTs at various NaCl concentrations.Monotonically decreased fluorescence intensity of ssDNA-SWCNTs with NaCl concentration varying from 100 mM to 5 mM, indicating that the surface coverage of DNA on SWCNTs varied with the ionic strength of the solution.

Figure S5 .
Figure S5.Statistical results of DCD width on SWCNTs with (GT)20 ssDNA at different NaCl concentrations.

Figure S6 .
Figure S6.Schematic diagram of ssDNA winding model on SWCNT surface.

Figure S9 .
Figure S9.Assembly yield analysis of HDC /LDC SWCNTs on DNA origami (released scaffold loop strand as "capture ssDNA").Compared with HDC-SWCNTs, the assembly efficiency of LDC-SWCNTsorigami is significantly improved.

Figure S10 .
Figure S10.AFM images of single LDC-SWCNT positioning on the surface of DNA origami breadboard.Unassembled: white solid boxes; assembled: red solid boxes.Scale bars: 200 nm.

Figure S11 .
Figure S11.AFM images of two LDC-SWCNTs positioning on the surface of DNA origami breadboard.No SWCNT attachment: white solid boxes; one SWCNT attachment: green solid boxes; two SWCNTs attachment: red solid boxes.Scale bar: 100nm.

Figure S12 .
Figure S12.Origami dimers were built via the connection of bridging strands to provide a larger template for SWCNTs arrangement.a) Larger DNA origami breadboard built via bridging strands.b) Accurate arrangements of SWCNTs with spacing from 54 nm to 30 nm.Scale bars, 50 nm.

Figure S14 .
Figure S14.Schematic representation of DNA origami template using released scaffold loop strand as "capture ssDNA" by removing edge staples.

Figure S15 .
Figure S15.Schematic representation of one row of capture ssDNA protruding from the surface of DNA origami for the assembly of a single LDC-SWCNT, highlighted in red.

Figure S16 .
Figure S16.Schematic representation of two rows of capture ssDNA protruding from the surface of DNA origami for the assembly of LDC-SWCNTs, highlighted in red.

Figure S17 .
Figure S17.Schematic representation of DNA origami as a breadboard for logical computation, highlighted in red.
Distance statistics of precise arrangement of SWCNTs with spacing from 54 nm to 30 nm.

Table S2 .
Assembly yield analysis of SWCNTs using DNA origami template with scaffold loop strand as "capture ssDNA" under different salt concentrations.

Table S3 .
Yield of single HDC/LDC-SWCNT positioning on the surface of DNA origami breadboard.
TableS4.Yield of two LDC-SWCNTs positioning on the surface of DNA origami breadboard.